Question: Solve for $x$ and $y$ using substitution. ${x-2y = -3}$ ${x = -6y-11}$
Since $x$ has already been solved for, substitute $-6y-11$ for $x$ in the first equation. ${(-6y-11)}{- 2y = -3}$ Simplify and solve for $y$ $-6y-11 - 2y = -3$ $-8y-11 = -3$ $-8y-11{+11} = -3{+11}$ $-8y = 8$ $\dfrac{-8y}{{-8}} = \dfrac{8}{{-8}}$ ${y = -1}$ Now that you know ${y = -1}$ , plug it back into $\thinspace {x = -6y-11}\thinspace$ to find $x$ ${x = -6}{(-1)}{ - 11}$ $x = 6 - 11$ ${x = -5}$ You can also plug ${y = -1}$ into $\thinspace {x-2y = -3}\thinspace$ and get the same answer for $x$ : ${x - 2}{(-1)}{= -3}$ ${x = -5}$